Red in images

[desler]

I'm still playing around with the now, becoming usual set up. Taking advice, I've pushed the ISO up but tend to get very red sky pics.

I've tried editing it out in Gimp after stacking in Deep Sky Stacker, but don't seem to be doing as well as I was at Lower ISO.

Any idea's would be appreciated.

Darren

[multiweb (Marc)]

If you're talking about this particular shot I reckon your colors are spot on. It's actually quite a nice shot.

[gbeal]

Try a Levels or Curves in Photoshop, and select the red channel. See if a little there helps. I agree with Marc, it is a good shot, but I can see what you mean in the "black" section of the sky.
Gary

[RB (Andrew)]

Originally Posted by desler

Any idea's would be appreciated.

Darren

Darren you have bias in the red colour channel.
You need to raise your black point in the red channel to get all three channels in the histogram to line up equally.

I've attached your histogram to show where the total histogram shows two humps due to the red bias level.

[spearo (Frank)]

Darren,
a bit hard to say, not sure how long your exposures are and at what ISO or whether your auto guiding or not.
However, having a look at the image you attached, the red I see in there is all nebula
nothing wrong with the presence of the red i see in there, in fact lots of subs or long duration should reveal it even more
frank

[desler]

Fantastic RB, Probably over done in my excitement, but the new knowledge will stop me sitting here to the wee hours scratching my head.

For info sakes.

18 x 70 second exposures, Combination of 800 and 1600 ISO, 1000D through ED 80 on eq6 pro. Nil guiding. Stacked in Deep Sky Stacker and levels and Crop in Gimp.

Still haven't got the illuminated eyepiece to start the daunting task of drift alignment, but I'm moving along.

Thanks again guys, this is great. new knowledge and a fair bit of data from last night. Oh the pressure!

Darren

[rat156]

One more tip Darren.

When you post the image, try to use a little less jpg compression. I know getting them down to 200k is difficult, but I would prefer to see a smaller pic without so much jpg rubbish.

Other than that, it's a great picture.

Great clear skies 'round our neck of the woods over the past few days. I'm not getting much sleep, but I'm loving it.

Cheers
Stuart

[desler]

Thanks Stuart,

Wasn't sure why the last image went like that, jpeg compression!
I think this one looks better. Thanks for the help!

Darren